Fungus Gnat


Actual Size: 1/10 to ⅛”

Characteristics: Gray or black with smoke-colored wings. Occasionally orange or yellow.

Legs: 6

Antennae: Yes

Wings: Yes

Habitat: Frequently infests humid or damp areas such as the bathroom, kitchen, or near leaking faucets.


  • Flourishes in environments with lots of moisture.
  • Weak fliers that often stay close to potted plants.
  • Larvae cause damage to plants by feeding on roots.

Fungus Gnats in Memphis TN Metro Area

Fungus gnats are tiny, delicate insects with long wings and thin legs. Sometimes, they can become bothersome in homes and businesses, especially when ferns and other houseplants that have organic-rich soil serve as their breeding grounds. The larvae of these gnats primarily feed on fungi and organic matter found in the soil, but they can also damage roots, making them a concern in greenhouses, nurseries, and indoor plant setups. Adult fungus gnats are attracted to light and are often first noticed around windows or light fixtures.

Fungus Gnat Habitat

In outdoor environments, fungus gnats are drawn to dampness, and issues may arise in regions where excessive watering has affected the landscape or in low-lying areas that retain excessive moisture after heavy rain. When indoors, fungus gnats are enticed by light and can be observed hovering around windows. However, in comparison to house flies, fungus gnats are not strong fliers and typically stay close to potted plants. They can also be discovered in areas of high moisture within homes, such as kitchens, bathrooms, laundry rooms, and crawl spaces.

Fungus Gnat Behaviors, Threats, or Dangers

Adult fungus gnats do not bite or harm plants; their main impact is that of an annoyance. The real culprits responsible for the damage are the fungus gnat larvae. When these larvae are present in large quantities, they can harm roots and impede the growth of plants, especially in seedlings and young plants. In interior plantscapes and houseplants, extensive root damage and even plant death have been observed when there are high populations of fungus gnats in moist, organic soil. Therefore, a houseplant that is wilting may not indicate a lack of water, but rather root damage by fungus gnat larvae.

If you’re experiencing a fungus gnat issue, contact your local fly control professional.